Demo of little known and previously lost predecessor to
BreakThru! and both were developed by ZOO Corporation (credited to Steve Fry) as variations of
SameGame by "Kyoto" (Eiji Fukumoto), which in turn was a variation of the original game that spawned this genre:
Chain Shot by "Morisuke" (Kuniaki Moribe).
It seems that shortly after its release this game was rebranded and re-released as BreakThru!
The website notes there was an earlier release of a UNIX version, though I'm yet to find any surviving supporting evidence of this.